According to JustJared.com, Mayer took his costume as the vampire hunter to Perry's vampire very seriously. The 35-year-old guitar virtuoso appeared almost completely unrecognizable by sporting a prosthetic nose and chin to complete the look. The birthday girl's crimson lips, fangs and velvet cape made for the perfect sexy vampire, and the location couldn't have been more fitting: L.A.'s Magic Castle delivered a haunted-house vibe right in the heart of Hollywood.

Instead of gifts, Perry requested that partygoers make donations in support of the David Lynch Foundation for Transcendental Meditation, a charity that provides free meditation instruction to inner-city children and veterans. Urging fans to do the same, Perry tweeted, "Transcendental Meditation changed my life. For my birthday I would love to pay it forward. In lieu of gifts, donate."

It's been a week of bicoastal birthday celebrations for the reunited couple. Perry helped Mayer celebrate the big 3-5 at Freeman's restaurant in New York with a dozen of Mayer's close friends.